Just 34 hours after the European Space Agency's Sentinel-1A spacecraft separated from its carrier rocket, it nearly smashed into a dead NASA satellite.

Costing $380 million, the Sentinel-1A is the first of a fleet of satellites that Europe is sending into space for its multibillion-dollar Copernicus project, which the ESA describes as "a new era in Earth observation."

That era nearly ended before it had a chance to begin. On the ESA website, the Sentinel-1A team has blogged about what it was like being in the control room:

As the first day shift nears its end, a serious alert is received: there is a danger of a collision with a NASA satellite called ACRIMSAT, which has run out of fuel and can no longer be maneuvered. Not much information at the beginning, we are waiting for more information, but a collision avoidance maneuver may be needed."Are you kidding? A collision avoidance maneuver during LEOP [Launch and Early Orbit Phase]? This has never been done before, this has not been simulated!"

It is decided to maneuver Sentinel-1A. Its orbit altitude needs to be changed to escape the chaser. Decision taken: this maneuver is the first one of the mission.

We are ready for the maneuver that takes 39 seconds….The atmosphere was tense and the Main Control Room was filled with suspense. Eyes were looking up at the big screens on the wall, waiting for a sign. As the satellite approached Troll ground station on the next pass and the telemetry started to scroll down in the twilight of the control room, the team hold their breath… ... Yes! the maneuver has been successful!

For the first time that night, loud laughs and cheers bursts through the room. We are safe.

Another ordinary night in the Sentinel-1 project life over, it is the turn of the day shift team to play with the baby now.

There's a certain karmic irony to this incident, since, just a couple of days ago, the International Space Station had to perform a maneuver to avoid debris from a European Ariane-5 rocket.